The number of prescriptions issued to children for anti-depressants, anti-psychotic drugs and attention deficit disorder medication has rocketed, according to figures released today.

The increasing use of drugs to treat mental health problems in youngsters is condemned by the Conservative Party which obtained the statistics from the NHS Prescription Pricing Authority.

Following a series of Freedom of Information requests, the authority revealed that more than 420,000 prescriptions of ADHD (Attention Deficit Hyperactivity Disorder) drugs were issued to children under 16 in 2007 – a rise of 33 per cent over the previous two years.

For those aged between 16 and 18, more than 40,000 prescriptions were issued – an increase of 51% compared to 2005. The NHS spent over £17m on ADHD drugs in 2007.

The number of prescriptions is not the same as the number of patients since some children may receive repeat or multiple prescriptions. The increase nonetheless suggests doctors are frequently resorting to pharmaceutical remedies rather than talking therapies.

Around 113,000 prescriptions for antidepressants were issued to children under 16 in 2007 and almost 108,000 to 16 to 18 year-olds, according to the same series of FoI requests. For children under 16, that respresented a 6% increase over two years. The NHS spent around £1.5m on anti-depressant drugs for children in 2007.

For anti-psychotics, in excess of 86,000 prescriptions were issued to children under 18 in 2007. The number given to 16 to 18 year-olds was up 7% since 2005 and the number handed out to under 16s rose by 11%. The NHS spent almost £3.5m on anti-psychotic drugs for children in 2007.

The Conservative health spokeswoman, Anne Milton, said: "We already know that our children suffer the lowest levels of well-being in Europe. This data shows that increasingly health professionals are prescribing drugs to treat child mental health problems, when evidence suggests that talking therapies can have an equal, if not better effect.

"These drugs have significant risks when given to children and young people, making this rise extremely concerning." Some drugs prescribed for mental health conditions have been associated with potentially dangerous side-effects in children, the Conservatives said. In one US study children reported experiencing hallucinations after taking ADHD drugs.

The Prescription Pricing Authority, which has itself since been subsumed into the NHS Business Services Authority, stopped collecting the data in late 2007 and said that it could no longer provide reliable estimates.

Earlier this year the British Medical Journal estimated that up to 5% of school age children in England and Wales have ADHD - as many as 367,000 children.

Responding to the figures a department of health spokesperson said: "NICE guidance is clear that antidepressants should rarely be prescribed to children and young people and only as part of a treatment regime, stressing that other treatment options should be considered first."

In terms of ADHD medication, the spokesperson added: "Treatment with prescribed drugs should only be started after a specialist in ADHD has thoroughly assessed the child or adolescent and confirmed the diagnosis. Once treatment has been started it should be monitored by a GP. Drug therapy should be one part of a comprehensive treatment programme that includes advice and support to parents and teachers."